Steam-engine



(No Model.) 4 Sheets-Sheetl M. G. BULLOCK. I

' STEAM ENGINE.

No. 533,157. Patented-Jan. 29, 1895.

(No Model.) 4 Sheets--Sheet 2.

M. G. BULLOCK.

STEAM ENGINE.

No. 533,157. Patented Jan. 29, 1895.

4 Sheets-Sheet 3.

M. G. BULLOCK.

(No Model.)

STEAM ENGINE.

No. 533,157. Patented Jan. 29, 1895.

THE uonms vzrzns co. HOIO-LITHO., WASHINGTON. n. c.

(No Model.) v '4 Sheets-Sheet 4.

.M. C. BULLOCK.

STEAM ENGINE.

No. 533,157. Patented Jan. 29, 1895.

. w 1 444 II w: Norms PETERS co, wuoraumo, WASHINGTON. n, 0

FFIQEQ ATENT MILAN O. BULLOCK, OF CHICAGO, ILLINOIS.

STEAM-ENGINE.

SPECIFICATION torml'ng part of Letters Patent No. 533,157, datedJanuary29, 1895.

Application filed August 8, 1893.

To whom it may concern: I

Be it known that I, MILAN O. BULLOCK, of Chicago, in the county of Cookand State of Illinois, have invented certain new and useful ImprovementsinSteam-Engin'es; and I do hereby declare that the following is a full,clear, and exact description thereof, reference being had to theaccompanying drawings, and to the letters of reference marked thereon,which form a part of this specification.

This invention relates to improvements in reciprocating steam engines ofthat class known as single-acting engines, or those in which the steamacts on one side of the piston only.

The engine herein shown as embodying my invention is of that kind knownas a double tandem compound engine, the sameembodying verticallyarranged, single acting cylinders, supported on a common base, twopiston rods carrying the pistons which operate within the cylinders, anda single crank-shaft pro vided with two cranks on which the two pistonrods severally act. The pistons being moved in one direction only by thesteam pressure within the cylinders as in other single-acting enginesand the return stroke of each piston rod being accomplished by theaction of the crank-shaft.

In the accompanyingdrawingsillustrating my invention, Figure 1 is a viewin side elevation of a double expansion engine embodying the same. Fig.2 is a central vertical section, taken axially through both cylinders.Fig. 3 is asectional plan view taken through both cylinders on lines 3-3of Figs. 1 and 2. Fig. 4 is a similar sectional view taken on lines 4-4:of Figs. 1 and 2. Fig. 5 is an enlarged detail section-0f the uppercylinder and adjacent part of the lower cylinder of the engine. Fig. 6is a detail plan section of the lowermost piston, taken ou line 6-6 ofFig. 5. Fig. 7 is a detailsection of the exhaust valve ring shown inFig. 6. Fig. 8 is a detail sec tion of the plate which covers theexhaust valve ring. Fig. 9 is adetail section through the lower or basepart of the engine, showing devices for giving motion to the steam inletvalves, the same being taken'on line 9-9 of Fig. 2. Fig. 10 is a plansection ofthe parts shown in Fig. 9, taken on line 10-10 of said Fig. 11is a detail section taken on figure.

Serial No. 482,669. (No model.)

line 1.i1l of Fig. 9. Fig. 12isa similar section taken on line 12-12 ofFig. 9.

As illustrated in said drawings, the base of theengine on which thecylinders and other parts are supported consists of ahollow casting A,within which is mounted the crank shaft B, which is arrangedhorizontally within said base and has suitable bearings therein, and isprovided with two cranks B B. Attache'd to the top of the base castingA, side by side, are two upright cylinders O O, which constitute thelow-pressure cylinders of the engine, and which are provided below theirupper ends with integral horizontal partitions or diaphragms O O formingthe heads of the cylinders proper. 'Said cylinders O C are open at theirlower ends and communica'te with the interior of the hollow base castingA, which is provided in its horizontal top wall with openings preferablysomewhat larger than the interior diameters of the cylinders; thecylinders being bolted to the said base casting in the mannerillustrated. Said base casting is provided at som'edist'ance below itstop wall with a horizontal partition or diaphragm A, which forms apassage or receiver for exhaust steam from the low pressure cylinders OC. Said base casting is also provided above the diaphragm A with an exitpipeA communicating withthe said exhaust passage or receiver andpermitting the discharge of the exhaust steam from the engine.

Affixed to the upper ends of the cylinders O O are other smallercylinders D'D, which constitute the high pressure cylinders oftheengine. Said cylinders D D open at their lower ends into the cylindersC- C, above the diaphragms O C of the latter, and are pro vided atpoints below their upperends with horizontal partitions or diaphragms]D' D which form the cylinder heads; The upper ends of said cylinders DD are closed by means of castings or heads E E, which form with theupper parts of the said cylinders above the diaphragms or partitions D'D steam chests or chambers E E, which are supplied with steam by meansof a steam supply pipe E leading to one of said chambers, and ahorizontal steam pipe E which connects the said chambers with eachother. As herein shown and as preferably constructed, the steam pipe Eis cast integral with the heads E E.

The upper parts of the cylinders O above the diaphragms O O constitutesteam cham- 5 hers or receivers between the high and low pressurecylinders, and inasmuch as the cylinders D D open at their lower endsinto the said steam chambers or receivers, the lower parts of saidcylinders D D below the pistons constitute in effect portions of saidreceivers. Similarly, the lower parts of the low pressure cylinders G Gopen into and form parts of the receivers or exhaust space in the upperpart of the base casting. (3 D indicate severally pistons which arelocated within the cylinders C and D, and F F are hollow or tubularpiston rods which pass through the several cylinder heads or diaphragmsO D and to which the several pistons C D are attached. The said pistonrods are herein shown as made in several separate parts or sections F FF of which the part F is attached to the upper piston D and extendsupwardly through the partition D into the steam chest. The part F isattached at its opposite ends to the pistons (J and D and the part F isattached to the piston C and serves to connect the same with thecrankshaft. The several diaphragms O and D are 0 provided with glands orpackings c d to make tight joints around the piston rods where thelatter pass through said diaphragnis. The piston rods F are providedabove the piston D with portsf for the admission of steam to the 3 5cylinders D and below said piston with other ports f for the admissionof steam from the receivers to the interior of the hollow piston rod,and similarly said hollow piston rod is provided above the piston O withsteam ports 0 f for the admission of steam to the low pressure cylinders0.

Within the base casting A are located two vertically arranged aircylinders G G which are in axial alignment with the low pressure 4 5steam cylinders O C, said air cylinders being closed at their upper andopen at their lower ends. Within the air cylinders G G are locatedpistons G G to which the lower ends of the piston rods F F are rigidlysecured.

The lower parts or sections F F of the piston rods F F pass throughglands or packing boxes g g in the heads g g of the air cylinders, whichglands or packing boxes form tight joints about the piston rods toprevent the escape of air past the cylinder heads. The pistons G G ofthe air cylinders are connected with the cranks B B of the crankshaft bymeans of connecting rods H H which are pivotally connected with thepistons and are engaged with the crank-pins in the usual manner. Saidpistons G G have preferably the form of hollow cylinders closed at theirupper ends, the upper ends of the connecting rods H H being locatedwithin the same and 6 5 pivotally connected therewith by bearin g pins gwhich are inserted transversely through the opposite side Walls of thepistons.

The air cylinders and the pistons described serve the same purpose asthe cross-head guides and cross-heads commonly employed for the purposeof guiding the piston rods of steam engines. Said air cylinders andpistons also serve as a means of taking up the momentum of the pistonsand piston rods during their up-stroke and to thereby maintain theconnecting rods compressed at all times during such stroke; it beingobvious that compression of the air in the air cylinders in theup-stroke of thepistons will gradually retard the movement of the pistonrods and connected parts. The energy expended in thus compressing theair is not lost for the reason that during the subsequent down stroke ofthe pistons the expansive action of the air is added to the effect ofthe steam pressure. Said air cylinders G G areshown as provided with airinlet openings 9 q for the purpose of admitting air to the cylinders ateach down stroke of the pistons.

In the particular construction shown the air cylinders are secured attheir upper ends in the partition A, the heads 9 9 being secured to thecylinders by bolts which also connect the cylinders to the saidpartition. A horizontal partition A located at some distance below thepartition A is provided with apertures in which the lower ends of theair cylinders closely fit and by which they are held accurately inplace.

Steam enters the upper ends of the several cylinders through the hollowor tubular piston rods F F and act on the upper surfaces of the pistonsto force the same downwardly or toward the open ends of the cylindersand the cranks being set opposite each other or at an angle of onehundred and eighty degrees one piston is at the limit of its down strokeat the time the other piston is at the limit of its up stroke, so thatthe up stroke of each piston rod is accomplished by the action of thecrank-shaft only. In the up stroke of the piston rod and pistonsattached thereto exhaust steam from the upper ends of the high and lowpressure cylinders escape into the receivers between said cylinders andbelow the low pressure cylinders through apertures or steam ports formedin the pistons themselves; suitable valves being provided in connectionwith said ports in the pistons to close the same except when they areopen for the passage of exhaust steam. The passage of steam through thehollow piston rods to the several cylinders is controlled by valveslocated within the hollow piston rods which valves are operated byactuating devices which extend through the hollow piston rods, and whichalso serve to actuate the valve plates by which the exhaust ports withinthe pistons are also actuated. Steam supplied to the steam chests E Eenters the open upper ends of the piston rod sections F F and isdelivered to the high pressure cylinders D D through the ports ff whichare located adjacent to the upper pistons. Steam from the receiversbetween the high and low pressure cylinders enters the inviously filledthe cylinders above the pistons will have passed through the pistons andwill fill the lower portions of the cylinders as well as the receiverswhich in the case of the high pressure cylinders is formed by the spaceabove the diaphragm C of the low pressure cylinder and in the case ofthe low pressure cylinder is formed in the upper part of the basecasting.

As far as the construction herein shown of the devices for admittingsteam to the several cylinders is concerned, these parts are constructed as follows: The movable parts of the several valves consist ofval ve-plugs I I which are located within the hollow piston rod and Iare attached to a common valve stem J, which extends centrally throughthe hollow piston rod and is adapted to turn or rotate with the valveplug. Said valve plugs are arranged to operate in connection with theports ff and are for this purpose located within the hollow piston rodsabove the pistons C and D and are arranged to fit closely within saidpiston rods. The several valve plugs are provided with ports or passages'i t' t" t" which open through the sides and upper ends of the plugs andcorrespond in width and angular arrangement with the ports f f f f inconnection with which they operate. Inasmuch as the several ports 11 zt" 11 of the valve plugs open at their upper ends into the hollow pistonrods, said ports are at all times in communication with the source ofsteam supply and it follows that when the ports are turned into positionto bring the said ports opposite to ports fff f of the piston rod, steamwill pass from the piston rods to the cylinders, but when the plugs areturned to bring the said ports opposite the spaces between said ports"f]" f, then the passage of steam will be cut off. As herein shown, theports ff of the piston rod are four in number, while the valve plugs arealso provided with four ports it, and it follows that in the operationof the valve the plug is swung or oscillated through an angular distanceequal to one eighth of an entire revolution, an oscillatory movementthrough this distance obviouslyserving to alternately open and close thevalve ports.

As shown in the drawings, Figsl 5 and 6, the valve plugs are in positionfor the admission of steam to both cylinders, the steam at such timepassing from the space within the upper piston rod section downwardlythrough the ports or passagest'tand then laterally outward through theports ffto the space within the cylinders above the piston Dtwhilesimilarly, steam which enters the piston rod section F through the portsf passes downwardly through the ports t" i and then laterally outwardthrough the ports f f to the space above the piston 0 In order toprovide ample area for the passage of steam with a minimum ofoscillatory movement in the valve, the ports f are made of considerablelength vertically and relativelynarrow, this construction having theadvantage also of giving sufficient area in the ports without undulyweakening the piston rod. The said ports when thus made of considerablevertical length will extend upwardly into the piston head or diaphragmwhen the piston is at the upward limit of its stroke, as seen at Fig. 5,but this is of no consequence in the operation of the engine for thereason that only a small supply of steam is required for starting thepiston in its down ward movement and as soon as the piston has moved farenough to acquire any considerable speed the ports will have beenentirely uncovered and an ample supply of steam thus afforded as soon asrequired.

The exhaust ports or passages c d which are formed in the pistons arearranged at equal distances apart around the pistons and separated fromeach other by spaces somewhat greater in length circumferentially thanthe ports themselves, while the annular valve plates or rings.K K areprovided with correspondingly arranged apertures k k is, these portsbeing so arranged that by turning the valve plate through an angulardistance equal to one half of that between the centers of two adjacentports said ports will be alternately opened and closed. The pistons andvalve plates are herein shown as provided with four ports or openings,the same corresponding in number with those of the steam inlet valve, sothat both the steam inlet and exhaust valves maybe operated by the sameactuating devices.

Means for connecting the said valve plates K K with the valve stem J areherein shown as provided as follows: Attached to the said valve platebelow the valve plugs I I are disks L L which are provided with radialarms 11 Z Z, which latter extend outwardly through suitable slots orpassages formed in' the pis tons and engaged at their outer ends withrecesses k 70 which are formed in a downwardly extending flange Won thevalve plate; said disk and arms thereon partaking of the oscillatorymovement of the stem J. It follows that the valve plates K K will bemoved or oscillated with the valve plugs I I, so that when the steamadmission valves are closed the exhaust valves will be opened and viceversa. It follows from this construction. that when the valve plugs areturned in one position steam will be admitted simultaneously to boththe'high and low pressure cylinders, and when the several plugs areturned in the opposite direction the steam will be cut oifsimultaneously from both cylinders and exhaust steam will be allowed toescape through the pistons from the spaces above to the spaces below thesame.

The upper valve plug 1 is provided on its top surface with a valve diskM, which is interposed between the ports of said valve plug and thesteam space of the steam chest and forms the movable part of the cut offvalve for controlling the steam supply to the high pressure cylinder inquantities corresponding with the work being done by the engine, therebysecuring the results produced by other cutoff valves. Said valve disk Mrests directly upon the top of the plug 1 and is provided with aplurality of ports m m corresponding in size and angular distance apartwith the ports or passages z" t of the said valve plug. Said cut oifvalve is attached to a valve stem N which passes downwardly through thevalve-stem J of the main valve, which latter valve stem is made hollowfor this purpose.

Inasmuch as the valve stems J' and N of both the main and cut off valvesare located within and moved longitudinally with the piston rod, devicesforturning or giving oscillatory movement to said valve stems mustobviously be connected to the same by devices permitting freereciprocation of the said stems with the piston rod while maintainingconstantly such engagement as is necessary for turning or givingoscillatory movement to the said stems. The devices herein shown asemployed for this purpose are located within the base A of the engineand are adapted to engage with the lower ends of said valve stems whichextend past the lowermost piston (J into the part of the hollow pistonrod below the said lower piston.

To now describe more specifically the devices shown for giving motion tothe valves, the main valve stem J is attached at its lower end to a diskJ which is adapted to turn freely within the hollow piston rod, whilethe valve stem N is attached to a similar disk N located below andpreferably adjacent to the disk J. Outside of the hollow piston rod andsurrounding the same are two rings 0 P, the ring 0 being attached to thedisk J by means of pins 0 extending through horizontal slots 0 0 in thepiston rod and secured in said disk J (Fig. 11). The ring P is similarlyattached to the disk N by means of pins 10 p which pass throughhorizontal slots pp in said piston rod. Q is an oscillating ring mountedon the top wall of the air cylinder G concentrically with the pistonrod, and R is a similar ring located outside of the ring Qconcentrically therewith. The ring Q is shown as held in place byengagement with the ring R, which is arranged to overlap the same, whilesaid ring R is shown as held in place by an external bearing ring Rsecured to the margin of the air cylinder head in the manner shown. Thering Q is provided with two vertical arms q q (Figs. 9 and 11) whicharms are provided with grooves to engage outwardly extending lugs on thering 0, so that said ring has vertically sliding but non-rotativeconnection with the said arms. The ring R has similar upwardly extendingarms 1* (Figs. 10 and 12) which arms have grooves on their inner facesengaging lugs on the ring P, so that said ring P has vertically slidingengagement with the arms 1" but is held in rotative engagementtherewith. The vertically sliding but non-rotative connection of thearms q q and r a" with the rings 0 and P obviously enables theoscillatory movement given to the rings Q and R to be transmitted to thedisks J and N and thence to the valve stems at all times notwithstandingthe rapid reciprocatory motion of the piston rod and said valve stems.

S. and T are two horizontally arranged actuating rods through the mediumof which motion is given to the rings Q and R, and which are themselvesactuated by suitable connections with the main shaft of the engine. Saidrods S and T are shown as extending through the base casting at one sideof the piston rods and as passing through packing boxes 8 t at thepoints where they enter the base casting. At their opposite ends saidrods are supported in guides s 25 attached to the wall of the basecasting within the same. The actuating rods S T are connected with theoscillating rings Q and R by means of short connecting rods or links ST; the link S being pivoted to the connecting rod and to an outwardlyprojecting lug g on one of the arms (1 of said ring Q, while the link Tis pivoted directly to the top surface of the ring R. It is obvious thatwith this construction endwise reciprocatory motion given to the twoactuating rods S and T will transmit oscillatory motion to the rings Qand R for the purpose of actuating the main and cut oif valves in themanner above described.

Means for giving motion to the actuating rods S and T of the main andcut off valves are provided as follows: On the main crankshaft B aremounted two eccentrics U and V, of which the eccentric U is rigidlyattached to the shaft and the eccentric V is loosely mounted thereon sothat it may be turned or partially rotated relatively to the shaft. Inconnection with the eccentric V is employed a governing device, hereinshown as having the form of a fly-wheel governor; said governing devicebeing arranged to turn the eccentric in one direction or the other,according to the speed of the fly-wheel. With the eccentrics U and V areconnected in the usual manner, two eccentric rods U and V, the upperends of which are connected with and give motion to two rock-shafts U V,(which rock-shafts are mounted in brackets U c attached to the basecasting A) and are provided with horizontal arms to u to the outer endsof which the eccentric rods U V are connected. The rock-shaft U isprovided with an upwardly extending arm a which at its upper end isconnected with the outer end of the valve actuating rod S; the means ofconnection shown consisting of two pivot links a a Similarly therock-shaft V is provided with an upwardly extending arm 12 the upper endof which is connected with the valve actuating rod T by means of twopivot links 11 The rock-shafts and arms thereon arranged as describedconstitute obviously, bell-crank levers by which the vertical motion ofthe eccentric rods is changed to horizontal motion for actuating therods S and T. The connecting devices constructed as described ovbiouslyserve to transmit motion continuously and uniformly from the eccentricsU and V to the valve actuating rods S and T at all times during theoperation of the engine.

The fly-wheel governor hereinbefore mentioned is shown as applied to thebelt pulley B of the engine and is constructed as follows, to wit: Theeccentric V is attached to a sleeveWwhich surrounds and turns on theshaft B and is provided with a rigidly attached radial arm to, Fig. 1.Pivotally mounted at one side of the pulley is alever W carrying aweight to at one end and connected at its opposite end by a link 20 withthe arm to of the eccentric sleeve. A spring W attached to the wheel rimis connected at its free end with with the weighted end of i the lever Wby means of a strap or cord w the spring being arranged to hold theweight normally at the inward limit of its movement. The parts of thegovernor are arranged in the usual manner so that the spring will tendto hold the eccentric normally in the position giving a maximumadmission of steam to the high pressure cylinder, while the outwardmovement of the weight produced by the increased speed of the engineacts to shift the eccentric in a manner to move the cut off valverelatively to the main valve in a direction to decrease the steamsupply.

The attachment of the piston rod sections to the pistons and the detailsof construction in the pistons by which suitable hearings or seats areprovided for the valve plates or rings K K may be of any suitablecharacter, the details of construction in these parts herein providedfor convenience in the construction illustrated being as follows: Thepistons each consist of a single casting made Without any passage oropening at its center excepting a bearing aperture for the passage ofthe valve stem J. Both adjacent ends of the piston rod sections aboveand below the piston are provided with an outwardly extending flange,and the piston rod sections are secured to the piston byvertical bolts 001 (Figs. 5 and 6) which pass through said flanges and the central partor hub of the piston in a direction parallel with the axis of the pistonrod. valve plates are stems are inserted The arms ZZ by which theconnected with the valve beneath the flanges of the through an angulardistance equal to somewhat more than one eighth of a circle at each sideof the center of the piston, l have found it desirable to arrange thebolts 0 0 close together in the spaces between the ends of saidrecesses, as clearly seen in said Fig. 6. Said bolts 0 c furthermore,are shown as engaging at their lower ends holding rings 0 placed incontact with the flange of the lowerpiston rod section and as engaged attheir upper ends with a plate K which extends over the valve ring K andcovers the top of the piston; said plate being extended inwardlytooverlap the flange of the upper piston rod sec tion and thus form aholding ring for the same. A depending flange Z0 on the plate K servesto fill thespace between the inner margin of the valve ring and theflange of the upper piston rod section, as clearly seen in Figs. 5 and6.

I claim as my invention- 1. The combination with singleacting high andlow pressure cylinders and an intermediate receiver in opencommunication with the high pressure cylinder, of a piston in the lattercylinder provided with exhaust ports extending directly through thepiston, and a valve for controlling said exhaust ports, substantially asdescribed.

2. The combination with single acting high and low pressure cylindersand an intermediate receiver in open communication with the highpressure cylinder, of a piston in the latter cylinder provided withexhaust ports extending directly through the piston, a valve forcontrolling said exhaust ports, and means for actuating said valveembracing parts which extend through the piston rod, substantially asdescribed.

3. The combination with a single acting cylinder and an adjacentreceiver into which the cylinder opens at one end, said cylinder beingprovided with a steam inlet port and a valve for controlling the same,of a piston in the cylinder provided with exhaust ports extendingdirectly through the same and with a valve for controlling said exhaustports consisting of a valve plate having port openings correspondingwith those of the piston, substantially as described.

4. The combination'with a cylinder and an adjacent receiver into whichthe cylinder opens at one end, of a'piston in the cylinder provided withexhaust ports and with a valve for controlling said exhaust ports themovable part of which is adapted to turn about an axis coincident withthe central longitudinal axis of the cylinder, substantially asdescribed.

5. The combination with a cylinder and an adjacent receiver into whichthe cylinder opens at one end, of a piston in the cylinder provided withexhaust ports, a valve for controlling the passage of steam through saidports, the movable part of which is adapted to turn about an axiscoincident with the central axis of the cylinder, a hollow piston-rod attached to the piston, and valve-actuating devices extending through thehollow piston-rod and connected with the movable part of the valve,substantially as described.

6. The combination with a cylinder and an adjacent receiver into whichthe cylinder opens at one end, of a piston in the cylinder provided withexhaust ports, a valve for controlling the passage of steam through saidports, the movable part of which is adapted to turn about an axiscoincident with the central axis of the cylinder, a hollow piston-rodattached to the piston, and valve-actuating devices embracing a stemwhich extends longitudinally through the rod and moves endwise with thesame, and means having sliding but non-rotating connection with the saidrod for giving motion thereto, substantially as described.

7. The combination with a cylinder and an adjacent receiver into whichthe cylinder opens at one end, of a piston in the cylinder provided withexhaust ports, a valve for controlling the passage of steam through saidexhaust ports, a hollow piston-rod provided with steam ports and a valvefor controlling the passage of steam through said piston-rod,substantially as described.

8. The combination with a cylinder and an adjacent receiver into whichthe cylinder opens at one end, of a piston in the cylinder provided withexhaust ports, a valve for controlling the passage of steam through saidexhaust ports, a hollow piston-rod provided with steam ports, a valvecontrolling the passage of steam through said piston-rod and means foractuating both of said valves embracing a valve stem which extendsthrough the hollow piston-rod and is connected with the movable port ofboth valves, substantially as described.

9. The combination with a cylinder and an adjacent receiver with whichthe cylinder communicates, of a piston in the cylinder provided withsteam ports, a valve for controlling said steam ports, the movable partof which is adapted to turn about an axis coincident with the centralaxis of the cylinder, a hollow piston-rod provided with steam ports avalve for controlling the passage of steam through said piston-rod, themovable part of which is also adapted to turn about an axis coincidentwith the central axis of the cylinder and means for actuating both ofsaid valves, embracing a valve stem which extends through the hollowpiston-rod and is connected with the movable part of both of saidvalves, substantially as described.

10. The combination with a cylinder and an adjacent receiver with whichthe cylinder communicates at one end, of a piston in the cylinderprovided with steam ports, a valve for controlling said steam ports, themovable part of which is adapted to turn about an axis coincident withthe central axis of the cylinder, a hollow piston-rod provided withsteam ports, a valve for controlling the passage of steam through saidpiston-rod, the movable part of which is also adapted to turn about anaxis coincident with the central axis of the cylinder, and means forgiving motion to both of said valves, embracing a valve rod or stemmounted to turn within the hollow piston-rod and movable endwise withthe same, the actuating devices having sliding but non-rotativeconnection with said rod or stem, substantially as described.

11. The combination with a cylinder and an adjacent receiver into whichthe cylinder opens at one end, of a piston in the cylinder provided withexhaust ports, a valve ring or plate operating in connection with saidports to form a valve for controlling the passage of steam through thesaid piston, a hollow piston-rod, a valve stem mounted to turn withinthe hollow piston-rod and connected with the said valve ring, and meansfor actuating said valve stem comprising parts having sliding butnon-rotative connection with the same, substantially as described.

12. The combination with a cylinder and an adjacent receiver into, whichthe cylinder opens at one end, of a piston in the cylinder provided withexhaust ports, a valve ring operating in connection with said valveports, a hollow piston rod provided with a steam valve, the movable partof which is adapted to turn about an axis coincident with the centralaxis of the cylinder, and means for actuating said valves embracing avalve stem mounted to turn in the said hollow piston-rod and connectedwith the movable part of said steam valve and with the said exhaustvalve ring, substantially as described.

13. The combination with acylinder and an adjacent receiver into whichthe cylinder opens at one end, of a piston in the cylinder provided withexhaust ports, a valve ring operating in connection with said valveports, a hollow piston-rod provided with steam ports, a valve forcontrolling said steam ports, the movable part of which is adapted toturn about an axis coincident with the central axis of the cylinder, andmeans for actuating said valves, embracing a valve-stem mounted to turnin the said hollow piston-rod and connected with the movable part ofsaid valve and with the said valve ring, and embracing also a part IIChaving longitudinally sliding but non-rotating connection with the saidvalve sten1,substantially as described.

14:. The combination with a cylinder and an adjacent receiver into whichthe cylinder opens at one end, of a piston in the cylinder provided withexhaust ports, a valve ring operating in connection with said exhaustports,

a hollowpiston-rod provided with steam ports, a valve-plug turning inthe hollow piston-rod and controlling said steam ports, and means foractuating the said valves embracing a valve stem mounted to turn in saidhollow piston-rod and connected with. said valve plug and with the valvering of the exhaust valve, substantially as described.

15. The combination with high and low pressure cylinders and anintermediate receiver separated from the low pressure cylinder by adiaphragm or partition forming the cylinder head, of pistons within saidcylinders, said pistons being provided with exhaust ports, valvescontrolling said exhaust ports, a hollow piston-rod attached to the saidpistons and passing through said cylinder head,

said piston-rod being provided with steam ports, valves for controllingthe passage of steam through the hollow piston-rod, and means foractuating the said valves embracing a valve rod or stem mounted to turnwithin the hollow piston-rod and connected with the movable parts ofsaid valves, substantially as described.

In testimony that I claim the foregoing as my invention I affix mysignature in presence of two witnesses.

MILAN O. BULLOCK.

Witnesses O. CLARENCE POOLE, ALBERT H. GRAVES.

